Category III missions to Mars (flybys and orbiters), as well as cruise stages, as stated in Section 5.3.1.2 of NPR 8020.12D, shall avoid Mars impact at a probability no less than 0.99 for 20 years after launch and a probability no less than 0.95 for the period 20-50 years after launch.

All Category IV missions to Mars shall meet the following bioburden constraints, as deemed appropriate given the mission type and needs, and as approved by the NASAPPO.

The following table provides the bioburden values for Mars Category IVa, IVb, and IVc missions.

Bioburden
levels or other values are dependent upon experimental needs.

Sub-System

IVc

Special Region is
Within the Landing Ellipse

Full-System

< 30

< 0.03

1.5×104
– sBbSL

–

0.1

< 1.5×104

Special Region is
Outside or Sub-Surface to the Landing Ellipse

Full Systemi

< 30

< 0.03

1.5×104
– sBbSL

–

0.1

< 1.5×104

Special Region is
Outside or Sub-Surface to the Landing Ellipse

Sub-Systemj

< 30 subsystem

< 0.03
subsystem

5×105
– Total sBbSL

< 5×105

1000

–

< 3×105
Total sBbSL

< 300 Total ρsBbSL

Missions that May
Induce or Create a Special Region

Full-Systemk

Bioburden
levels or other values are dependent upon experimental needs.

Sub-Systeml

a.For all missions,
the soft-landed hardware must be protected from recontamination due to the
hard-impacting hardware and other components of the spacecraft.

b.Includes only
hard-impacting hardware that is within 3 σ of the landing ellipse.

c.Includes all
hardware (soft-landed and hard-impacting hardware) that is within 3 σ
of the landing ellipse.

d.Includes only
accessible or exposed surfaces.

e.Includes all
surfaces and encapsulated and mated materials of the hard-impacting hardware.

f.Includes components of the spacecraft that
may release spores into the environment, including the accessible surfaces of
the soft-landed hardware and all components of the hard-impacting hardware.

g.Includes all
non-accessible surfaces of the soft-landed hardware.

h.Includes all
surfaces and encapsulated and mated materials of the soft-landed and
hard-impacting hardware.

i.Full-system option will be employed if the
spacecraft carries a long-term heat source (e.g., plutonium) or failure modes
analysis of the landing event indicates that debris field could contaminate a
special region at a probability >1%.

j.Sub-system option may be employed if failure
modes analysis of the landing event indicates that debris field would not
contaminate a special region at a probability >1%.

k.Full-system option will be employed if
failure modes analysis of the landing event indicates that debris field could
create a special region at a probability >1%.

l.Sub-system option may be employed if failure
modes analysis of the landing event indicates that debris field will not
create a special region.